Official Freewing B-2 Spirit Bomber 86" Twin 70mm EDF Jet

[GliderGuy]

Has anyone solved the flutter issue? I do have the programming card as well. What all is done?

Do you mean control surfaces moving and working to keep cockpit in front and wheel side down?

There’s no reported flutter issues.

-GG

[MeyerVW]

Higher speeds the aircraft is oscillating. The gains are maybe a bit high. Some one took out 50% and in the video the aircraft flies pretty good.

[mshagg]

There are gyro oscillations in some scenarios which are obvious in the videos where that is ocurring. I've bumped the roll gains down 10% as a starting point and increased stick priority (changing gain drop curve to 'sport') but also have remote gain on a dial. Also bumped yaw gains down to 85% (from default 100%).

The pitch axis gain is so low that it is effectively an unstablised axis. It will be interesting to see how it responds to any increase.

[kallend]

Higher speeds the aircraft is oscillating. The gains are maybe a bit high. Some one took out 50% and in the video the aircraft flies pretty good.

That is not flutter. Flutter is an aeroelastic instability, not a gyro induced oscillation.

It really helps to use the correct nomenclature.

[Aros]

Regardless of nomenclature or semantics, it seems like at top speeds there is a shudder - gyro induced or not - that has been reported. Not that I proclaim to have the answer but just as a comment I would simply say this is not a model meant to be flown like a F-18 or any other fighter. This is a model meant to be flown scale-like...Half speed, 3/4 speed tops...Just enjoy her for what she is meant to be. (Not pointing fingers, simply a statement from what I have read and seen so far).

[GliderGuy]

The smoothness of the air has a lot to do with how much, if any, control action / slight wiggles will occur as well as altitude.

In calm air without turbulence regardless of speed….she’s rock solid and plenty fast at max throttle.

Bring her by low and fast or even moderately fast when the air is rough and you will see the control action and perceive slight wiggles.

Do the same pass again up high, and you can barely see the action.

Hit a BIG turbulent bump, she may jump as she fights it!

It’s all in what one wants to see and in what air conditions one wants to fly in and how fast.

if the slight (and it is slight) wiggle bothers you, then fly in calm/smooth air. Or spend the time experimenting with the gyro / control box set ups.

To each his own. Tweak away! Part of the challenges of the hobby that some like to do.

IMHO, she’s fine stock, and I accept the slight wiggles when flying in bumpy air or windy conditions. I have elected to NOT mess with the setup. My other birds wiggle too in windy and rough conditions. Said another way and after making many, many B-2 flights, I don’t perceive that there is a design/setup issue. She’s good!

I’m simply glad I have a B-2 that is well designed, and flies well to have fun with and enjoy watching fly by.

-GG

[Evan D]

Excellent post, I agree 100%!

The smoothness of the air has a lot to do with how much, if any, control action / slight wiggles will occur as well as altitude.

In calm air without turbulence regardless of speed….she’s rock solid and plenty fast at max throttle.

Bring her by low and fast or even moderately fast when the air is rough and you will see the control action and perceive slight wiggles.

Do the same pass again up high, and you can barely see the action.

Hit a BIG turbulent bump, she may jump as she fights it!

It’s all in what one wants to see and in what air conditions one wants to fly in and how fast.

if the slight (and it is slight) wiggle bothers you, then fly in calm/smooth air. Or spend the time experimenting with the gyro / control box set ups.

To each his own. Tweak away! Part of the challenges of the hobby that some like to do.

IMHO, she’s fine stock, and I accept the slight wiggles when flying in bumpy air or windy conditions. I have elected to NOT mess with the setup. My other birds wiggle too in windy and rough conditions. Said another way and after making many, many B-2 flights, I don’t perceive that there is a design/setup issue. She’s good!

I’m simply glad I have a B-2 that is well designed, and flies well to have fun with and enjoy watching fly by.

-GG

[MeyerVW]

Why does every question end with arguments. All I want to do is tame the aircraft a bit. I agree it flies very good as is. Just want to sweak it a bit to my personal liking. Not trying to break any speed records here.

[Flying Dutchman]

Probably, it is a matter of choosing your wording more carefully.

Your initial question could be read as some sort of criticism, by your statement that the B2 had ‘flutter issues’.

In your posting above, you reply that you ‘want to tame the aircraft a bit’. Also suggesting that there is something amiss with the aircraft’s design, in your opinion.

That leads to responses that you would not be looking for.

[GliderGuy]

Why does every question end with arguments. All I want to do is tame the aircraft a bit. I agree it flies very good as is. Just want to sweak it a bit to my personal liking. Not trying to break any speed records here.

No arguments offered…no offense intended / only personal perceptions about a non-major (IMHO) flight characteristic.

Tweak away/experiment until you are satisfied.

Others may provide the feedback you seek based upon their knowledge.

So, help everyone by confirming you specifically intended to ask for tips on optimal gyro settings….right? Nothing more. I was mislead.

-GG

[kallend]

Why does every question end with arguments. All I want to do is tame the aircraft a bit. I agree it flies very good as is. Just want to sweak it a bit to my personal liking. Not trying to break any speed records here.

Maybe you should have framed your original question more carefully.

[Soonerflyer]

Should CG be obtained gear up or gear down?

[GliderGuy]

Should CG be obtained gear up or gear down?

Opinions vary….summarizing from historical posts:

1) Most time is spent flying with gear up, so set CG with gear up.
2) What about when the gear is lowered? Since you are “on the sticks” more in the pattern, it is a non-issue.

My B-2 experience: I am slightly nose heavy with wheels down. So, I mixed in some added “up” for when the wheels are down and at low power settings. I get rid of the extra “up” during wheels up/cruise flight.

Works for me. Other opinions will no doubt vary.

-GG

[xviper]

Opinions vary….summarizing from historical posts:

1) Most time is spent flying with gear up, so set CG with gear up.
2) What about when the gear is lowered? Since you are “on the sticks” more in the pattern, it is a non-issue.

My B-2 experience: I am slightly nose heavy with wheels down. So, I mixed in some added “up” for when the wheels are down and at low power settings. I get rid of the extra “up” during wheels up/cruise flight.

Works for me. Other opinions will no doubt vary.

-GG

My thoughts exactly. Ask yourself .................. Do you fly this plane with the wheels down most of the time? Or do you fly it wheels up? With me, wheels are down when taking off and when landing. During those scenarios, I'm constantly on the sticks to change the plane's attitude and flight pattern. Compensating for CG at those times is easier. During those times when are less on the sticks is when flying steady state cruising - the wheels are up then and that's usually when you trim the plane for level flight "hands off".

[radfordc]

Should CG be obtained gear up or gear down?

This answer is not specific to the B-2.

You don't want the CG to be so far aft that the plane is difficult to control.

If a plane's CG shifts aft when the gear is retracted (Corsair, P-40, etc) you should probably set the CG with the gear retracted. This ensures that the CG won't be too far aft. When the gear is extended the CG will shift forward some but this isn't a problem.

For a plane whose CG shifts forward when the gear is retracted (C-47, A-10, etc) balance with the gear extended. Again, the CG will shift forward slightly when the gear is retracted.

Once you have established that the plane is fully controllable at the most aft CG location you can begin to make small adjustments to improve flight characteristics.

[MeyerVW]

No arguments offered…no offense intended / only personal perceptions about a non-major (IMHO) flight characteristic.

Tweak away/experiment until you are satisfied.

Others may provide the feedback you seek based upon their knowledge.

So, help everyone by confirming you specifically intended to ask for tips on optimal gyro settings….right? Nothing more. I was mislead.

-GG

Yes, thats what I was trying to get at. Fine tune it to my flying.

[mshagg]

I get that this is a motionRC forum but it would also help if people weren't overly sensitive about perceived criticism of a model.

There's no good reason to run a gyro at the ragged edge of over controlling the model. Period. The few extra % that causes it doesn't make a model's flight characteristics any more accessible. Nor is there a good reason to ship a B2 with Atti lock as a selectable flight mode. Its possible to call out these decisions while still being in awe of what they have brought to the market.

[Aros]

I am happy to report I have the perfect color match for this B-2. The guy at Home Depot NAILED IT. I can't even see where he put the test dab on the hatch. It's that good.

Here's the lid...

[GliderGuy]

Aros- What is the left-most numbers / characters?

0Z
884th?

Thanks!

-GG

[Evan D]

I do it gear down just to make it easy to check sitting there. But I determine what I want for a balance point by flying it and then seeing where it is setting on the ground on its gear. I then mark where that spot is under the canopy.